It is known to employ a burner assembly to produce a burner flame for the purpose of drying aggregate materials such as those that are used in the production of hot mix asphalt (“HMA”). However, conventional burner assemblies suffer from several disadvantages. For example, conventional premix burner assemblies have inherent burner flame stability problems, particularly in the lower portion of the range of operation of the burner flame. In addition, conventional premix burner assemblies experience undesirable flashbacks by the burner flame which occur when the burner flame propagates back up from the burner end of the burner assembly into the body of the burner assembly.
It would be desirable, therefore, if an apparatus and method could be provided that would produce a stabilizing base flame for the premix main burner flame in a burner assembly. It would also be desirable if such an apparatus and method could be provided that would improve the stability of the premix main burner flame in a burner assembly, particularly in the lower portion of the range of operation of the premix main burner flame. It would be further desirable if such an apparatus and method could be provided that would reduce the incidence of undesirable flashbacks and blow offs by the premix main burner flame. It would be still further desirable if such an apparatus and method could be provided that would enhance the mixing of stabilizing base flame fuel with main combustion air so that the stabilizing base flame may be run throughout the entire firing range of the burner without adversely affecting the quality of the combustion emissions. It would also be desirable if such an apparatus and method could be provided that would enhance the stabilizing characteristics of the premix stabilization base flame and enable the combustion of leaner premix gas mixtures, thereby improving the stability of the base flame so that it may be run safely throughout the entire firing range of the burner, including higher main flame ranges with very lean mixtures. It would be further desirable if such an apparatus and method could be provided that would produce a symmetrical center base flame pattern that fills any vortices produced by the main flame and improves the shape of the main flame.